This invention relates to body massage apparatus and, more particularly, to body massage apparatus for administering controlled massage actions to a person's body by vibrating a body support structure.
Two types of apparatus have heretofore been used for administering massage actions to a person's body by vibrating a body support structure. In the simplest of the two types of such apparatus, a motor is energized by a signal of constant frequency to vibrate the body support structure. The constant frequency of the motor energizing signal induces an unchanging vibration in the body support structure. The unchanging vibration transmits a concomitant unchanging vibratory effect to the occupant of the body support structure. While the unchanging vibration produces a rudimentary massaging effect, it is incapable of a varying stimulation of the body. Furthermore, some persons find an unchanging vibration to be disturbing rather than soothing. One example of a massage apparatus of the foregoing type is described in U.S. Pat. No. 3,050,051.
The second of the two types was resorted to in an attempt to obviate the aforementioned limitations and disadvantages. This second type uses wave interference to create a vibration pattern that travels about the body support structure. The traveling wave can transmit a continuously changing stimulation to occupants of the body support structure if the apparatus is operated to propagate the proper wave disturbance. To create a propagated wave disturbance, however, it is necessary to employ at least two vibrator motors to vibrate the body support structure at two different points selected so that the wave disturbance produced by each of the motors interacts with that produced by the other motor in the manner required to effect a traveling wave. This is achieved by utilizing at least two motor energizing signal sources and operating them to generate two signals slightly out of phase with respect to each other, so that the motors are driven at slightly different speeds. Examples of such apparatus are described in U.S. Pat. Nos. 3,019,785; 3,547,109 and 3,653,375.